As an Owner Opperator it depends on the customer and the load details. In the case with an under load breakdown.
First call your customer, load broker, carrier, and/or fleet owner and ask them what they want you to do. Dont jusk "What do I do?" Give them the following options
1) Tow the truck to a shop, Tranfer to a rent a wreck, as soon as you can get one and finnish the job.
2) Pay serious bucks to have the truck repaired if you cannot find a replacement vehical.
3) Eat the cost to hire annother company to cover the run knowing in most cases it will be more expensive than doing it myself.
4) Be prepared to discount the rate in order to satisfy the customer and compensate him/her for the inconvience for the delay.
I had one situation where the customer had annother truck and it was a mater of transfering the load over. Luckily, I broke down less than a mile away. It still cost me 100 bucks that blew my paycheck for the job but Everyone was happy and the job got done.
Either way it will cost you time and money, and you need to be in good comunication with your customer, load broker, carrier, and/or fleet owner and follow THIER DIRRECTIONS .